A propeller having a means for creating fluid flow in a non-axial direction and redirecting it in an axial direction.

An aircraft with the capability of taxiing with main engines off uses the energy stored in a mechanical flywheel to power a propulsor(s) providing taxiing thrust. The flywheel can store energy generated by the propulsor operating as a wind turbine and/or by a power turbine in fluid coupling with the exhaust of a gas turbine engine and/or an expansion turbine operating with bleed and/or APU air.

An aircraft with the capability of taxiing with main engines off uses the energy stored in a mechanical flywheel to power a propulsor(s) providing taxiing thrust. The flywheel can store energy generated by the propulsor operating as a wind turbine and/or by a power turbine in fluid coupling with the exhaust of a gas turbine engine and/or an expansion turbine operating with bleed and/or APU air.

A propeller includes a blade. The blade includes a blade root, a blade tip disposed away from the blade root, a blade front surface, and a blade back surface. The blade also includes a front edge connecting a first side of each of the blade front surface and the blade back surface. The blade also includes a rear edge connecting a second side of each of the blade front surface and the blade back surface. The blade further includes a first suppression member formed by a portion of the front edge adjacent to the blade tip bending toward a first direction. The first direction is a direction from the front edge to the rear edge. The first suppression member is configured to suppress a spanwise air flow.

In one embodiment, a method includes fastening a plurality of components of a composite structure in an assembly fixture, wherein the assembly fixture comprises a plurality of strands of a fiber-reinforced thermoplastic material, wherein the fiber-reinforced thermoplastic material comprises a thermoplastic embedded with a plurality of reinforcement fibers, wherein the plurality of reinforcement fibers is aligned within each strand of the plurality of strands, and wherein the assembly fixture further comprises an anisotropic thermal expansion property based on an orientation of the plurality of reinforcement fibers within the assembly fixture; and heating the assembly fixture in an autoclave to bond the plurality of components of the composite structure.

In one embodiment, a method includes fastening a plurality of components of a composite structure in an assembly fixture, wherein the assembly fixture comprises a plurality of strands of a fiber-reinforced thermoplastic material, wherein the fiber-reinforced thermoplastic material comprises a thermoplastic embedded with a plurality of reinforcement fibers, wherein the plurality of reinforcement fibers is aligned within each strand of the plurality of strands, and wherein the assembly fixture further comprises an anisotropic thermal expansion property based on an orientation of the plurality of reinforcement fibers within the assembly fixture; and heating the assembly fixture in an autoclave to bond the plurality of components of the composite structure.

A propeller system combines innovative strategies to create a new methodology to reduce propeller or rotor noise. The propeller is specifically aimed for ultra-quiet electrically powered aircraft for use in high proximity aviation, but its low-noise advantages will extend to other purposes. The propeller blade includes geometries, along with size and operational limitations that minimize rotational and vortex noise, vibration and span-wise air flow on the blade. To further reduce noise, the propeller provides greater relative thrust on the inboard portions of the blade than do conventional propellers and provides less than conventional relative thrust including negative thrust at the outermost portions of the blade. The propeller blade includes stepped changes in local blade stiffness at calculated intervals that can reduce resonant blade vibrations and their resultant noise. This ultra-quiet propeller design can also be used for quieting hovercraft, drones, surveillance aircraft, indoor fans, wind tunnels and other applications.

A propeller system combines innovative strategies to create a new methodology to reduce propeller or rotor noise. The propeller is specifically aimed for ultra-quiet electrically powered aircraft for use in high proximity aviation, but its low-noise advantages will extend to other purposes. The propeller blade includes geometries, along with size and operational limitations that minimize rotational and vortex noise, vibration and span-wise air flow on the blade. To further reduce noise, the propeller provides greater relative thrust on the inboard portions of the blade than do conventional propellers and provides less than conventional relative thrust including negative thrust at the outermost portions of the blade. The propeller blade includes stepped changes in local blade stiffness at calculated intervals that can reduce resonant blade vibrations and their resultant noise. This ultra-quiet propeller design can also be used for quieting hovercraft, drones, surveillance aircraft, indoor fans, wind tunnels and other applications.

A propeller having a plurality of blades extending radially outward from a hub, the blades forming a loop. Each loop having an intake portion, an exhaust portion and a tip portion extending radially outward from the hub and a gap between the intake root and the exhaust root. The tip portion of each of the blades is 30%-75% of the blade, the tip portion beginning at a first deviation from zero of the roll value and extending to 90 degrees, wherein roll value is zero in a plane parallel to the hub axis, and wherein the blades have a vertical angle between −45 degrees and 45 degrees throughout.

A propeller having a plurality of blades extending radially outward from a hub, the blades forming a loop. Each loop having an intake portion, an exhaust portion and a tip portion extending radially outward from the hub and a gap between the intake root and the exhaust root. The tip portion of each of the blades is 30%-75% of the blade, the tip portion beginning at a first deviation from zero of the roll value and extending to 90 degrees, wherein roll value is zero in a plane parallel to the hub axis, and wherein the blades have a vertical angle between −45 degrees and 45 degrees throughout.